Zap a Cocaine Addiction With … Lasers?

Scientists showed they could erase a rat's cocaine habit by shining a laser light on its brain. The achievement could give rise to a new therapy for people crippled by an addiction to the drug, researchers say.

For people and lab rats alike, a compulsive cocaine addiction can dull activity in the prefrontal cortex, a brain region thought to be important for impulse control and decision making.

In the new study, scientists used genetic engineering to transform neurons in the rats' prefrontal cortex into a switch. They implanted light-sensitive proteins called rhodopsins in the neurons that they could turn on and off with a laser light.

"When we turn on a laser light in the prelimbic region of the prefrontal cortex, the compulsive cocaine seeking is gone," said study researcher Antonello Bonci, scientific director of the intramural research program at the National Institute on Drug Abuse, part of the National Institutes of Health (NIH). [10 Odd Facts About the Brain]

Interestingly, the treatment can go both ways. Switching those neurons off turned the non-addicted rats into coke addicts.

The results offer promise that targeting the prefrontal cortex could be an effective therapy for humans. Bonci and his colleagues plan to begin clinical trials at NIH to see if this approach might work. The scientists say lasers wouldn't be used in the human version of the treatment, according to a statement from the University of California, San Francisco, which also contributed to the study. Instead, the therapy would likely use transcranial magnetic stimulation, a non-invasive method applied outside the scalp and has been used as a treatment for depression.

The clinical trials would probably involve a few sessions for people who are addicted to cocaine to test if activity can be restored in their prefrontal cortex to help them kick the habit.

The research was detailed this week in the journal Nature.

There have been other ambitious attempts to cut cocaine addiction. Last summer, two separate groups of researchers developed cocaine vaccines that showed promise in blocking the highly addictive drug before it reaches the brain.